If you cut the grasses back with electric hedge trimmers, you can cut them back in layers, so that the grass trimmings are cut into mulch and can be left in the beds.

I'm not really into dried flowers myself, but many of the grass plumes make spectacular dried flower arrangements.

Grassland Gardens in KS works with ornamental grass plumes for arrangements.

Here is a link that might be useful: Dried Floral - Ornamental Grasses

Mine goes on the compost pile! But I know what you mean, it seems like there must be something you can do with those dried grass stalks!

I did save some of the finer dried grass from Prairie dropseed to put in a suet cage I hang with nesting materials for the birds. I also put cat hair in there from my sister's long-haired cats that she brushes - the birds LOVE that they will pick out chunks of hair to line their nests.